Correlation of cell proliferation inhibition and apoptosis induction with expression of human beta 5 integrin on hematopoietic cells

Objective To investigate the function of the alpha v beta 5 integrin in hem atopoietic cells. Methods Tissue culture, integrin expression vectors, gene transfer, polymer ase chain reaction (PCR), apoptosis analyses and cytometic analysis were ma de on hematopoietic cells. Results The beta 5 integrin cDNA was not expressed in hematopoietic cells f ollowing exposure to the beta 5 integrin retrovirus vector pG beta 5CHT. Un balanced expression of the alpha v beta 3 and alpha v beta 5 integrins occu rred during apoptosis induced by serum depletion and upon differentiation. The treatment of hematopoietic cells with anti-alpha v beta 5 monoclonal an tibody inhibited apoptosis induced by serum depletion. inducible expression of the beta 5 integrin cDNA in the hematopoietic cell line K562 caused cel lular proliferation inhibition. Conclusion The alpha v beta 5 integrin cDNA in hematopoietic cells can inhi bit the proliferation of the hematopoietic cell, cause the differentiation of the hematopoietic cells and induce the apoptosis of the hematopoietic ce lls.